Abstract: Two employees of an electrical contractor went to a site to wipe down surfaces and vacuum the bottoms of 4,160-volt cubicles in an electrical room. They had a rag and Simple Green cleaning fluid. Neither employee had previously worked on equipment of this voltage, and the employees did not know the operating voltage of the equipment. The onsite employer racked out and locked the equipment to be cleaned, and Employee #1, an electrician, did a walk down with the employer to verify that the equipment was racked out. However, the two employees did not know that one of the cubicles remained energized from another source of electric energy. On the door of that cubicle was a red-stenciled sign that read, "CAUTION MAY BE ENERGIZED FROM AN ALTERNATE SOURCE." Neither employee noticed the sign, and the onsite employer did not mention the alternate energy source to the employees. The following day, after meeting with the onsite employer, the employees began to clean the cubicles. When Employee #2 was cleaning the still-energized cubicle, he felt a slight electric shock. He took out a 600-volt proximity tester, and it lit up without touching the conductors. Employee #1 retrieved a voltage meter rated for 750 volts and placed the meter leads on the conductors. The meter failed and the ensuing electric arc burned both employees. Employee #1 received second- and third-degree burns. He underwent skin graft surgery and was hospitalized for his injuries. Employee #2 was hospitalized for more than 24 hours. He received pain medication for his burns. (The original form did not list Employee #2 on an injury line.)